One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,5,4)(3,7,8,6)(10,14)(11,17)(16,22)(18,19)(28,36)(33,38)(35,37)(39,40)(1,3,5,8)(2,6,4,7)(9,10)(11,15)(12,16)(13,14)(17,21)(18,23)(19,24)(20,22)(25,26,31,30)(27,34,29,32)(28,33,36,38)(35,40,37,39)(9,10,13,14)(11,15,17,21)(12,16,20,22)(18,23,19,24)(25,27,31,29)(26,32,30,34)(28,35,36,37)(33,39,38,40)(9,10)(11,15)(12,16)(13,14)(17,21)(18,23)(19,24)(20,22)(25,28)(26,33)(27,35)(29,37)(30,38)(31,36)(32,39)(34,40) involution — undirected(1,4,5,2)(3,7,8,6)(9,11,13,17)(10,15,14,21)(12,19,20,18)(16,24,22,23)(25,29,31,27)(26,32,30,34)(28,37,36,35)(33,39,38,40)(9,12,13,20)(10,16,14,22)(11,18,17,19)(15,23,21,24)(25,30,31,26)(27,34,29,32)(28,38,36,33)(35,40,37,39)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.